Tiltable crucible or converter for refining crude iron



p 1961 P. PUXKANDL 3,000,621

TILTABLE CRUCIBLE OR CONVERTER FOR REF INING CRUDE IRON Filed March 5,1959 H \i k I 5b F/6.1

7b 7a 7 6a 6b INVENTOR.

P ETER PUXKAN DL [0L4 ATTo/eNeYs 3,000,621 v TILTABLE CRUCIBLE ORCONVERTER FOR REFINING CRUDE [RON Peter Puxkandl, Linz, Austria,assignor to Vereinigte Osterreichische Eisenund StahlwerkeAktieugesellschaft, Linz, Austria, an Austrian company Filed Mar. 5,1959, Ser. No. 797,507 Claims prio 'ty, application Austria Mar. 12,1958 4 Claims. (Cl. 266-39) Tiltable crucibles or converters forrefining crude iron consist of a cylindrical or pear-shaped vessel whichis provided with a refractory lining and the bottom part of which may beintegral with or removable from the shell part. The shell of suchcrucible is surrounded approximately on the level of the center: ofgravity by a supporting trunnion ring, which is rigidly connected to twotrunnions. By means of electric or hydraulic drive means connected tothe trunnions the crucible must be capable of being tilted from anapproximately vertical blowing position to an inverted position until itis completely emptied, and of being subsequently re-erected. Thetrunnion ring has the function of reliably holding the crucible in allpositions and of transmitting to the crucible the forces which areexerted by the drive means. The holding and guiding of the crucible mustbe effected in such a manner that expansion due to heat or refractorypressure is possible from the center of the crucible in four directions,preferably in the axis of the trunnions and at right angles thereto.This requirement can be complied with by the provision of so-calledclaws, consisting of short angle brackets, one flange of which isrigidly connected to the crucible wall, e.g., by riveting, whereas theother flange protruding from the outside wall of the crucible bears onthe trunnion ring. The protruding flange portion has a degree of freedomof movement in a centrifugal direction from the axis of the crucible.For this reason the trunnion ring must surround the Wall of the cruciblewith a clearance to permit of an expansion. The guides of the claws inthe direction of the trunnions have also the function of preventing aslipping of the crucible in any desired tilted position.

Four to eight pairs of claws spaced around the periphery of the cruciblehave previously been used for holding the crucibles and the supportingtrunnion ring was engaged without play by one protruding flange portionof each pair on the top and by the other protruding flange portion onthe 'bottom. This arrangement involved difliculties, however, becausethe support of the crucible in any other than the horizontal positionbecame one to five times statically indeterminate. This prevented anexact determination of the stresses. Because .safety considerationsrequire the dimensions of the trunnion rings to be calculated for theleast favorable stress cases, the trunnion rings become very heavy anduneconomical.

It is an object of the present invention to eliminate these difficultiesand to provide an improved mounting of the crucibles on the trunnionring to achieve a substantial reduction in weight and in material andprocessing costs.

The crucible or converter according to the invention comprises asupporting trunnion ring extending around the shell of the crucible andcomprises two trunnions, the ring being mounted between the protrudingflanges of pairs of claws spaced around the periphery of the crucible,and is characterized according to the invention in that only three pairsof claws are provided, with which the crucible firmly engages the topand bottom of the trunnion ring, two of said pairs of claws extendingdiametrically opposite each other in the plane of the trunnion axis ofthe carrying ring and the third pair of claws Patented Sept. I9, 1961extending in another direction, preferably at right angles to thetrunnion axis.

of the pairs of claws disposed in the trunnion plane. In any tiltedposition outside the vertical position the crucible rests with the upperclaws on three bearing points whereas the lower claws forrn guides. Thesame conditions exist beyond the horizontal tilted position when thoseflange portions which were previously the lower guide portions havebecome carrying bearing portions and the previously carrying upperportions have become guide portions. Thus, a three-point support, whichpermits of an easy statical analysis, is ensured in any tilted positionand the material expenditure required for the trunnion ring is muchreduced.

To guide the crucible in the case of heat expansion or deformation, thetrunnion ring is provided according to the invention on both sides ofeach claw with two guide rails, between which each protruding flange isslidable. In a preferred embodiment of the invention a guide is providednot only in the direction of the three pairs of claws but also in afourth direction, suitably opposite to the third pair of claws, in aplane which extends at right angles to the trunnion plane. In this casea fourth pair of claws with guide rails is arranged at this point andthe upper and lower flange portions of this pair of claws are slightlyspaced from the trunnion ring to permit of a free upward and downwardplay thereof. The height of the guide rails exceeds this play so thatthe fourth pair of claws, while it cannot take up hearing forces,cooperates with the rails to guide the crucible like the otherunstressed portions of the three other pairs of claws in the case ofheat expansion or deformation.

The invention is explained more in detail in the drawing. FIG. 1 is atop plan view and FIG. 2 a side view showing the trunnion ring and theclaws. FIG. 3 is a diagrammatic representation of the degrees of freedomof a crucible which is provided with the mounting according to theinvention.

The trunnion ring 2 surrounding the crucible shell 1 is rigidlyconnected to the two trunnions 3. The converter wall carries the pairsof claws 4 and 5 in the plane of the trunnions and the pairs of claws 6and 7 in a plane which extends at right angles thereto. Each pair ofclaws consists of upper and lower angle brackets. One flange of eachbracket (4a, 5a, 6a, 7a) is firmly connected to the crucible wall, e.g.,by riveting, and the other flange of each bracket (4b, 5b, 6b, 7b)protrudes at right angles from the crucible wall. The trunnion ring ismounted between the protruding flanges of the pairs of claws 4, 5, 6 sothat these flanges firmly engage the top and bottom of the trunnionring. On the other hand, a clearance 8 is provided between'theprotruding flanges 7b of the fourth pair of claws and the top and bottomof the trunnion ring so that the trunnion ring cannot take up bearingforces at this point. The support of the crucible is provided by meansof the other three pairs of claws 4, 5, 6. In the vertical position onlythe upper claws 4b and 5b and in any tilted position as far as to thehorizontal position only the upper claws 4b, 5b and 6b carry load. Thisensures a statically favourable three-point support in any position.

On both sides of each protruding flange (4b, Sb, 6!; and 7b) thetrunnion ring is provided with guide rails 10, between which eachprotruding flange is slidable. As is apparent from FIG. 2, such guiderails are also provided for the unstressed fourth pair of claws 7; theclearance 8 is less than the height of the rails 10 so that this pair ofclaws has approximately the same effect with respect to the guidance ofthe crucible in the case of heat expansion as the load-carrying otherpairs of claws.

FIG. 3 shows the degrees of freedom of the statically determinedthree-point support of the'crucible according to the invention. Atpoints 4, 5, 6 corresponding to the pairs of claws 4, 5, 6 the cruciblehas only one degree of freedom of movement, in the trunnion plane andat" right angles thereto, so that it is capable of free 'eXpan sion. Inpoint 7 of the unstressed pair of claws a de' gree of freedom ofmovement in the direction of the crucible axis exists in addition to thedegree of freedom of expansion at right angles to the trunnion plane sothat tilting forces will not be transmitted at this point.

What I claim is:

1. A tiltable crucible for refining crude iron compri's ing a crucibleshell of substantially circular cross-section, a ring surrounding saidshell, diametrically spaced trunnions extending outwardly from saidring, three pairs of angularly spaced-apart claws on said shell slidablyreceiving said ring and supporting said shell on said ring, two pairs ofsaid claws being arranged diametrically opposite each other on adiameter substantially coinciding with the axis of said trunnions andthe third pair of claws being interposed between said two pairs of clawsto pro vide for three point support of said shell on said ring.

2. The tiltable crucible set forth in claim 1 in which the said thirdpair of claws extends at substantially a Iright angle to the trunnionaxis.

3. A tiltable crucible for refining crude iron comprising a crucibleshell of substantially circular cross-section, three pairs of flangesextending outwardly from and spaced around the periphery of the saidshell, a ring ex tending around "said shell having upper and lower surfaces slidably engaging said pairs of flanges, diametri' cally spaced,coaxial trunnions extending outwardly from said ring, two pairs of saidflanges being arranged dia' metrically opposite each other on a diametersubstantially coinciding with the axis of said trunnions and the thirdpair of flanges extending at about a right angle to the trunnion axis toprovide three point support for said shell, pairs of guide railsextending from said ring on opposite sides of at least one flange ofeach pair of flanges and in slidable engagement therewith to positionsaid shell in said ring.

4. The tiltable crucible set forth in claim 3 comprising a fourth pairof flanges opposite said third pair of flanges on said shell in rightangular relation to the trunnion axis, said fourth pair of flanges beingspaced from the upper and lower surfaces of said ring so that they donot support said shell and guide rails on said shell 'slidably engagingthe sides of said fourth pair'of flanges.

References Cited in the file of this patent UNITED STATES PATENTS986,534 Woods Mar. 14, 1911 1,126,687 Beebe Feb. 2, 1915 2,301,880Johnston Nov. 10, 1942 2,823,028 MacGregor et a1 Feb. 11, 1958

